This invention relates generally to spring hinges for doors and the like, which are designed to exert a door-closing force; and more particularly to such a hinge which provides for selective adjustment of said door-closing force, wherein the hinge remains substantially unaffected by vibration or the like which may occur during use.
Many buildings and fire codes for hotels, motels, apartments and like structures require the installation of door closer devices. In many such cases it is both convenient and economical to provide spring door hinges for automatically closing the doors, rather than the more expensive and bulkier hydraulic closer units. Spring hinges are generally known in the art and are disclosed, for example in U.S. Pat. No. 3,903,567 and the art cited therein.
In the use of such prior art spring hinge devices, it has been found desirable to provide for loading of the spring at the installation site, and after door has been hung, further it is also desirable to select the amount of closing force to be exerted by such hinge structures at this time. More specifically, such prior art hinge structures have generally been provided with means for torsioning or preloading the coil or torsion springs therein, either during assembly at the factory, or during installation, to accommodate the particular application in which the hinge is to be used. Generally speaking, such hinge structures include a pair of adjacent leaves, each having at least one hinge knuckle in axial alignment with a hinge knuckle defined on the opposite leaf. A spring member is inserted through the knuckles, a first end of the spring being non-rotatably mounted to a plug or capstan member fixed for rotation in unison with one of the hinge knuckles. The opposite end of the spring is similarly non-rotatably mounted with a second plug or capstan member, which second member is free to rotate with respect to the opposite hinge knuckle. The desired degree of torsional force may be imparted to the spring member by rotating the second capstan member and then fixing it in position when such force is attained. Further, the second capstan member is generally provided with a plurality of circumferentially arranged sockets which are successively brough into registry with a through aperture in the associated knuckle as the capstan is rotated. Once the desired degree of torsional force has been attained, a suitable pin member is then inserted through the aperture and socket to maintain the capstan in a fixed position thereby maintaining the spring tension.
For numerous reasons, it is not practical to preload the spring at the factory. One reason is that different spring loadings are required for various types of doors and door mountings. A more important reason why it is desirable to tension the spring at the installation site, is that it is extremely difficult to hang a door using active spring hinges. Accordingly, the spring hinges of the prior art, like that of the present invention are designed to be torsioned after the door has been installed.
One significant problem that has arisen in the use of prior art spring hinges that are activated at the installation site is the maintaining of the pin member in position throughout the service life of the hinge. Many arrangements have been suggested including complimentarily threading of the retaining pin member and the capstan sockets; press fitting the pin member into the capstan socket; forming the pin member with the splines or knurles to bite into the capstan socket. It has been found, however, that with all of these arrangements the retaining pin member remains subject to gradual loosening, and ultimate disengagement from the capstan socket due to loading and shock forces, and the vibrational forces to which the hinge is subjected during operation. Moreover, where such press fitting or similar engagement arrangements are utilized, it is difficult, and often impossible, to reinsert the pin properly, once it has been removed, as would be employed in readjustment of the torsioning force. Accordingly, it is a general object of this invention to provide a door hinge of the type described which is relatively simple to adjust for the desired degree of torsional force, yet reliably maintains such adjustment, once made, and can easily be readjusted, should it be desired to change the amount of torsional door-moving force provided thereby.
Briefly, and in accordance with the present invention, there is provided a spring hinge comprised of a pair of adjacent hinge leaves, each leaf having at least one hinge knuckle on the opposite leaf. A spring mechanism is carried by the knuckles, having a first end non-rotatably affixed to a first capstan member or the like which is affixed to or integral with one hinge knuckle, and as such will rotate therewith. The opposite end of the spring is non-rotatably affixed to a second capstan member which is adjustably mounted in the opposite hinge knuckle. This second capstan member includes a plurality of circumferentially spaced sockets which may be successively brought into registry with a through aperture in the associated knuckle, upon rotation of the capstan to torsion the spring, and a retaining pin inserted through the hinge knuckle aperture to fix the capstan in position once the desired amount of spring force is attained. The pin member includes a first portion engaged in the socket and a second portion received in the aperture, said second portion being of a lesser diameter thereby defining a shoulder portion therebetween. Consequently, following insertion of the pin member, the spring force will tend to rotate the capstan, which is restricted by the pin, however, due to the reduced diameter of the second portion, slight movement will occur, moving the shoulder on the pin out of registry with the knuckle aperture. As such, inadvertent removal of the pin member is precluded due to the non-alignment of the shoulder with the aperture.
In a preferred embodiment, the pin member also includes an enlarged head portion severably or frangibly connected to the second portion and extending outwardly of the aperture portion for facilitating handling of the pin during insertion. The head portion is fractured after insertion of the pin member, to render the unit tamper-proof.
Other objects, features and advantages of the invention will become apparent upon reading the following detailed description with reference to the accompanying drawings, wherein like reference numerals refer to like parts.